Wiper Plug With Internal Pressure Chamber for Tubing Testing
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Solution Overview
Problem
Conventional methods often fail to perform a full pressure check on tubing strings cemented in boreholes due to the impracticality of deploying a plug for pressure testing after cementing operations.
Innovation Solution
The wiper plug design includes a body with uphole and downhole barriers and an internal chamber, allowing for high-precision pressure activation and removal of barriers to facilitate pressure testing without the need for additional plugs, using self-removable materials and temporary valves to ensure fluid communication after testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a deployed plug is used for pressure testing after cementing operations, then pressure testing capability is improved, but operational complexity and feasibility deteriorate
Solution Approach 1:
The patent combines the pressure testing function with the wiper plug used during cementing operations. The wiper plug integrates an internal pressure chamber, uphole barrier, downhole barrier, and temporary valve to perform both the cementing separation function and the pressure testing function, eliminating the need for a separate pressure testing plug deployment.
Solution Approach 2:
The wiper plug is designed as a multi-functional device that performs multiple operations: separating cement slurry from displacement fluid during cementing, maintaining pressure differential for precise activation, enabling pressure testing through integrated barriers and chamber, and ensuring subsequent fluid circulation through self-removal. This universal design resolves the contradiction by making the same device serve multiple purposes.
2Measurement precision
If additional plugs are deployed for pressure testing, then pressure testing precision is improved, but device complexity increases
Solution Approach 1:
The pressure testing mechanism is merged into the wiper plug structure itself. The internal pressure chamber, uphole barrier, and downhole barrier are integrated components that work together to enable precise pressure activation and testing without requiring additional separate plug devices.
Solution Approach 2:
The wiper plug is pre-configured with the pressure testing mechanism during manufacturing. The uphole and downhole barriers are pre-positioned within the throughbore, and the temporary valve is pre-installed, allowing the device to perform pressure testing immediately upon deployment without requiring additional complex deployment procedures.
3Ease of operation
If barriers are made removable for pressure testing, then pressure testing accessibility is improved, but structural integrity deteriorates
Solution Approach 1:
The barriers are designed with dynamic properties that allow them to transition from a strong, sealed state during pressure testing to a removable state when needed. The uphole barrier can be removed by applying pressure greater than the predefined activation pressure, while the downhole barrier can be removed by pressure or through self-removable material degradation, enabling both structural integrity during testing and accessibility when required.
Solution Approach 2:
The barriers utilize materials or mechanisms whose properties change in response to pressure or chemical stimuli. The self-removable material changes from a structurally intact state to a degraded state through exposure to solvents, acids, or other wellbore conditions, allowing the barrier to maintain strength during operation but become removable when activation conditions are met.
4Ease of operation
If self-removable materials are used for barriers, then barrier removal ease is improved, but material reliability deteriorates
Solution Approach 1:
The self-removable material is pre-configured to remain stable and reliable under normal operating conditions (cementing and pressure testing) but is designed to respond to specific activation stimuli. The material's removal properties are activated only when exposed to specific solvents, acids, or wellbore conditions, ensuring reliability during operation and ease of removal when needed.
Solution Approach 2:
The self-removable material acts as an intermediary between the barrier function and the removal function. During normal operation, the material provides structural integrity and sealing. When exposed to activation stimuli (solvents, acids, temperature), the material degrades or dissolves, facilitating barrier removal without compromising the barrier's reliability during its service life.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise pressure testing of tubing strings without requiring additional plugs, ensuring structural integrity and allowing for subsequent operational steps without disrupting fluid circulation.
Implementation Method 1
The chamber is enclosed in the throughbore between the uphole and downhole barriers and is configured to hold an internal pressure lower than the downhole pressures
Implementation Method 2
The self-removable material can be configured to dissolve, erode, disintegrate, or degrade due to heat, temperature, fluid, introduced solvent, applied acid, time, and/or a wellbore condition as the stimulus
Implementation Method 3
The temporary valve is configured to at least temporarily prevent pressure communication therethrough from the uphole end to the downhole end
Data Source
AI summary
A wiper plug is used in an operation to cement tubing in a borehole. The wiper plug is pumped down the tubing to separate an advancing fluid from a following fluid of the cementing operation, and an internal pressure chamber is maintained in a throughbore of the wiper plug between uphole and downhole barriers. The wiper plug eventually lands in the tubing, and the uphole barrier is removed by applying a first predetermined pressure against the uphole barrier. Removal of the uphole barrier is facilitated by the known and controlled internal pressure of the plug's chamber. The downhole barrier is also removed so that flow is permitted through the throughbore of the wiper plug. To perform a tubing pressure test, the downhole barrier can be removed due to pressure, and the chamber may have a temporary valve to hold applied pressure to a test level. Alternatively, the downhole barrier can hold the applied pressure. The temporary valve and the downhole barrier can then be self-removing in response to a stimulus.